Alkaline detergent compound



Jan. s, 1939.' L. A. HALL Er M 2,142,810

ALKALINE DETERGENT COMFQUNDy Filed April 50, 1937.

FIEL

Mrzreg Patented Jan. 3,

PATENT OFFICE- merma nErEnGEN'r ooMroUNn A. Holland Carroll L. Grimth, Chicago,

lll.,v assignors to The Grilth Laboratories, Inc., a corporation of Illinois Application April 30,1937, serial No. 139,860

14 Claims.

rlhe present invention relates to improvements in alkaline compounds and more particularly to partially hydrated alkaline phosphate carbonate compounds of a new type having a high degree of stability, especially in respect L'of their water content. The compounds preparedin ac.- cordance with the present invention are thus par kticularly suitable for use as detergents and in the preparation of alkaline detergent mixtures.

The alkaline phosphates and especially trisodium phosphate have been found to be highly desirable as detergents 'and as lconstituents of detergent compositions, particularly for the re.

moval of oil and grease from iron, steel, tinned and other metall surfaces, and from enamelware.

china, glass, stone, concrete and the like. In general, it has been found desirable to combine the trisodium phosphate with other alkalis, such as sodium hydroxide; or with various' auxiliary agents, particularly oxidizing agents such as hypochlorites, perborates or the like. The trisodium phosphates, in their usual hydrated forms are, however, unstable in respect of their water content, the dodecahydrate, readily giving up water, particularly in dry atmosphere; and the monohydrate tending to take up and collect moisture, particularly in humid atmospheres. Thus, normal changes in humidity of the air in rooms containing opened packages of these'materials lead to changes in composition and resulting changes of behavior, to caking or to wetting or deliquescence of the particles, either at and near the surface or throughout the entire mass of the package in some cases or to a 'greater or less de=4 gree of cfllorescence in others.' In any case, the material becomes unsightly and in many cases unusable.

The lack of stability of the moisture content ci the trisodium phosphates ls also disadvantageous in connection with their use in detergent compositions or admixtures, since it frequently leads to premature reaction and decomposition ofV the mixture, loss of effectiveness and to unsightliness and unusability of the products.

lt is an object of the present invention to prepare a trisodium phosphate compound of marked stability, not subject to changes appreciably afiecting .its physical Vor chemical characteristics as a result of the temperature and humidity changes to which it may ordinarily be subjected, and capable of .forming highly stable detergent compositions or mixtures.

In carrying out theppre'sentinvention, it has been the further objects thereof to maintain the detergent characteristics of trisodium phosphate,

`bonate or sodium sesquicarbonate.

without securing excessive or increased alkalinity or causticity, and to provide a compound of ready and rapid solubility.

In carrying out the present invention, we employ trlsodium phosphate together with a sodium carbonate compound of lowerhydrogen content than sodium bicarbonate, such as sodium carl It will be noted that the constituents used in carrying out the invention tend to combine with water in subl0 stantial' proportions to Y form crystalline compounds.

- The alkaline compounds formed in accordance with the present invention are new, stable hydrated compounds of trisodium phosphate and 15 sodium carbonate or sesquicarbonate wherein fraction pattern. The proportion of water present is in general from about l8 to about 25 or 26 percent, although products havingv the desired characteristics have been formed containing somewhat less amounts ci water. Where the characteristic sodium phosphate-carbonate compound of the present invention appears, the water content of the compound, within Athe range ci proportions mentioned, is hrmly held and the product shows a high degree of stability, with freedom. from calling, deliquescence and eiilorescence and forms stable mixtures with other substances readily ahected or decomposed oy water.

En the preparation of the alkaline products oi the present invention, the sodium phosphate and sodium carbonate compounds are employed in such molecular proportions as to provide :from about @.5 up to about 1.8 phosphate radicals to each carbonate radical, the preferred ratio being from 1 to 1.25 (P04) to 1(003). The sodium phosphate employed may be anhydrous or hydrated trisodium phosphate; the commonly available monohydrate or dodecahydrate may be used. Similarly, the sodium carbonate compound used may be anhydrous soda ash or hydrated sodium carbonate or sesquicarbonate. The selected sodium carbonate and sodium phosphate compounds,

' in the desired proportions, are mixed with a suitsolid constituents is tofbe avoided because of the increased time and expense of evaporation and p because in some cases it appears to prevent the' formation ofthe desired hydrated phosphate carbonate complex or compound. As the ratios of phosphate to carbonate approach the upper and lower limits of the ranges set forth, it appears important that lower proportions of water be used in preparing the slurry, substantially below and preferably below '75% of the solids initially used.

'I'he aqueous mixture is then subjected to evaporation over an open llame or on a drum dryer to reduce its water content to a point such that on cooling it rapidly congeals or solidies. The resulting mass is then broken 11D, ground or pulverized and dried, suitably at a temperature of to 140 C. and preferably in vacuo, to constant weight.

` The products prepared in accordance with the present invention are distinctive in that they contain and consist largely of a hydrated complex sodium phosphate and carbonate compound, and are hence highly stable in respect of their water content. 'Ihe precise composition of these products may vary to some extent, as some excess of either the carbonate or phosphate compound may be present without appreciably aiecting the stability of the product or its rapidity and cornpleteness of solution or eifectiveness of utilization.

In respect of the formation of Athe hydrated complex in accordance with the present invention, it will be noted that both the sodium phosphate and sodium carbonate constituents ofthe mixture tend to form crystalline hydrates containing considerable .proportions of water, and each appears to display a strong avidity for the relatively inadequate proportion of water available. As a result, the' resulting product, prepared as herein described, is very stable as to its water content and physical properties, and in each case a deiinite hydrated compound or complex of sodium phosphate and sodium carbonate is formed.

The products formed in accordance with the present invention are therefore particularly suited for use as commercial detergents, since Athey remain stable under varying conditions of temperature and humidity, and consequently maintain a constant and uniform`physica condition in opened and partly used packages. They may be prepared as stable powders of any desired degree of neness which are rapidly soluble and do not cake or become wet in opened packages. They are also excellent water softeners and improve the lathering qualities of soaps and the permanence of the lathers formed. As they are non-caustic, they do not injuriously affect the hands and skin of users.

The products of -the present invention have but l slight corrosive action upon tin and other metals (other than aluminum) commonly used as containers for culinary purposes, in dairies, bakeries and the like. They are rapid and eilective in their detergent action and in the removal of oily and greasy deposits, and are thus particularly useful in the cleaning of cooking, baking and dairy pans, vessels and utensils and in the cleanirliig of metal work, stone and cement. and the By rea son of their stability, the products of the Such excess over 45 or 50% of w'ater as,

present invention are also adapted to form detergent mixtures or compositions in admixture with other substances, particularly those which are readily affected or decomposed by moisture and hence cannot ordinarily be used with phosphates, carbonates and other detergent alkalies which readily yield a part of their moisture content or' which tend to deliquesce in humid atmosphere.

This hydrated complex or compound of sodium phosphate and sodium carbonate prepared in accordance with the present invention has a distinctive and identiable structure, as is clearly indicated by its X-ray diilraction pattern. The compounds` prepared in accordance with the present invention, when subjected to crystal analysis by X-ray diiraction, preferably by the powder method, display an unique crystal lattice spacing which is different and distinguishable from those of compounds hitherto known. Since, as is now well established, each crystalline substance is distinguishable by the kind and arrangement of the atoms and molecules making up the crystal and by the spacing between them; and that on passing an X-ray beam through the substance and permitting the diiracted beams to act on a photographic film or plate, a pattern is secured which is characteristic oi4 the substance. By passing a monochromatic beam of X-rays through a compacted powder mass and recording the diffracted rays 4upon ailat photographic vemulsion surface having its plane perpendicular to the incident beam, the diiracted beams will be recorded as a series of rings of varying spacings and intensities surrounding the central spot formed by the incident beam. By using a photographic emulsion surface or lm in the form of a cylindrical section with its axis perpendicular to the incident beam, on opening or unrolling the film, the diffracted beams will be recorded as lines spaced from the position of 1932, New York), pages 226 to 228 and 252, 253. l

In the accompanying drawing are illustrated diagrammatically the principal lines and spacing of the lines of X-ray diffraction patterns secured from powdered compounds prepared in accordance with the present invention, as hereinafter described. In the drawing:

Figure 1 shows diagrammatically the pattern obtained on use of a cylindrical cassette, the principal lines being indicated by straight lines; and

Fig. 2 shows diagrammatically the corresponding lines of the pattern as recorded on a flat film.

The characteristic lines and spacings of the patterns illustrated in the drawing are secured from products formed in accordance with my invention and`will be fully described hereinafter in connection with certain specific examples of the production thereof.

Example No. 1.-'150 pounds of trisodium phosphate (crystalline) and pounds of sodium sesquicarbonate are dissolved in about 100 gallons of water by heating to about 200 F. to eiect solution. The mixture is then subjected to rapid drying. Although in smaller quantities the drying or evaporation may readily be eected in open fired pans, in larger quantities it is preferred that the heating and drying be effected, for example, on a drying drum,suitably at a temperature above 300 F. After the drying operation. l5

the mass, which is in a fused or molten condition, is allowed to cool, and sets or congeals into avhard mass. This mass is then broken up and dr'ied at a temperature of 105 to 110 C. to constant weight. The resulting product is then pow'- dered. It is found to contain about 20% of water in combined form or as water of hydration. It is a stable compound, does not change or alter its characteristics nor cake on i standing with changes'in temperature and is rapidly soluble and has excellent detergent qualities. 0n X-ray analysis it records diffraction patterns having the principal characteristic lines and spacings as illustrated diagrammatically on the ilgures of the accompanyingdrawing, in which Fig. l shows the characteristic pattern as recorded on'a cylindrical nlm and Fig. 2 as recorded on a hat nlm.

The diagrammatic illustrationsv in the drawing show only the principal characteristic lines and their spacings and these lines may best be identied by reference to. the correspon crystal lattice spacings in Angstrom units according to the Bragg formula:

m=2d sin o Specinga corresponding Line No. to line centers (in 99. Pz 38a 2i 4N irait...

essence The principal ngures given for the spaclngs listed may be regarded as accurate to 0.01 A.. -`U. (101 cm1).

In the patterns illustrated, the lines designated 9 to I2 inclusive are' characteristic of hydrated sodium carbonate and indicate the presence thereof to a minor undetermined proportionv in as described in Example radicals to carbonate radicals is approximately` Example No. 2.--Nonnal trisodium phosphate, sodium carbonate and water are admlxed in the proportions of 2 parts by weight of the phosphate, 1 of the anhydrous carbonate and 3 of water, giving an initial ratio of 0.56 phosphate group to 1 `carbonate group. Instead of the normal trisodium phosphate, an equivalent amount (about 0.96 part) of the monohydrated compound may be used. Solution is effected by heating the mixture, which is then dehydrated on a drying drum as in the case of Example' No. l or by heating in a shallow evaporating pan until sputtering ensues, after which drying is continused at a temperature of 105-110 C. 'Ihe final product is suitably ground or powdered for use, and is. essentially similar in its properties and stability to the product made in accordance with Example No. 1. It contains 25.74% water (determined at 140" C.) and on X-ray analysis yields a diiraction pattern having the same characteristic lines and spacings as those of the product of Example No. vl. v l

Example No. 3.--3 parts by weight of the monohydrated trisodium phosphate, l of sodium sesquicarbonate and 2 of water/are mixed, heated to eect partial solution of the resulting slurry, and dried or dehydrated as described in connection with Example No. 2. The initial ratio of phosphate radicals to carbonate radicals is 1.8 to yl. The resulting product has a moisture content of about 23.2%.

Thexproduct of Example 3 is likewise stable and shows on X-ray analysis the characteristic diraction pattern illustrated in the drawing in connection with theproduct of Example No. 1. By reason of the high phosphate ratio of this product,4 the lines characteristic of the phosphates may accompany it.

In preparing the alkaline products of the present invention, anhydrous or monohydrated trisodium phosphate may be employed as well as the normal crystalline compound, and anhydrous or crystalline sodium carbonate or sesquicarbon- Aate may be employed. The proportions of these constituents employed may be varied and in some cases the proportion ci phosphate compound has been increased .to provide a ratio of phosphate groups to carbonate groups of almost 2:1 while maintaining to a large extent the stability of the product. In general, while such products, on X- ray analysis, show the characteristic diffraction pattern of the product of the present invention' as hereinbefore described, they may also show that characteristic of unreacted sodium phosphates.

Although the present invention has been described in connection with the details of specic examples embodying the same, it is not intended that these details shall be regarded as limitations on the scope of the invention, except in so far as included in the accompanying claims.

We claim:

1. The method of forming a stable alkaline cletergent compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises admixing a trisodium phosphate and a sodium carbonate compound of the class consisting of sodium carbonate and sodium sesquicarbonate and their hydrates in proportions to provide a ratio of about,0.5 to about 1.8 phosphate groups to each ,carbonate group with wa.-

ter in proportions of from about 45% upwardly y of said solid compounds to at least form a slurry and dehydrating the resulting mixture 'to form a stable, normally solid, pulverizable product, containing in stable combination fromv about 18 to about 26% of water.

2. 'I'he method of forming a stable alkaline detel-gent compound comprising principally a hydrated sodium phosphate and carbonate comabout 26% of water.

3. The method of forming a stable alkaline detergent compound comprising principally a. hy-

drated sodium phosphate and carbonate complex which comprises admixing a trisodium phosphate and a sodium carbonate compound of the class consisting of sodium carbonate and sodium sesquicarbonate and their hydrates in proportion to Vprovide a ratio of 0.5 to 1.8 phosphate groups to each carbonate group, adding water to the mixture in proportions of from about 45 to about 150% by weight of the mixture to at least form a slurry and dehydrating the resulting mixture to form a stable, normally solid pulverizable product containing in stable combination from about 18 to about 26% of water.

4. The method of forming a stable alkaline detergent compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises admixing a trisodium phosphate and a sodium carbonate compound of the class consisting of sodium carbonate and sodium sesquicarbonate and their hydrates in proportion to provide aratio of 1 to 1.25 phosphate groups to 1 carbonate group, adding water to the mixture in proportions of from about 45 to about 100% by weight of the mixture to at least form a slurry and dehydrating the resulting mixture to form a normally solid, vpulverizable product containing in sta-ble combination from about 18 to about 26% of water.

5. The method of forming a stable alkaline detergent compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises dehydrating an aqueous solution containing trisodium phosphate and a sodium carbonate of the class consisting of sodium carbonate and sodium sesquicarbonate in proportion to provide a ratio of 0.5 to' 1.8 phosphate groups to each carbonate whereby a stable product principally consisting of a hydrated complex` of sodium phosphate and sodium carbonate and containing from about 18 to about 25% of water is secured.

6. 'I'he method of forming a stable alkaline detergent compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises dehydrating an aqueous solution containing trisodium phosphate and a sodium carbonate of the class consisting of sodium carbonate 'and sodium sesquicarbonate in pro` portion to provide a ratio of 1 to 1.25 phosphate groups to each carbonate group whereby a stable product principally consisting of a hydrated complex of sodium phosphate and sodium carbonate `and containing from about 18 to about 25% of water is secured.

'7. The method of forming a stable alkaline detergent'compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises heating 750 parts of normal trisodium phosphate and 180 parts of sodium sesquicarbonate with water to eiect solution thereof, and dehydrating the mixture, thereby forming a stable product containing about 20% of water and consisting principally of a hydrated compound of sodium phosphate and sodium carbonate.

8. The method of forming a stable alkaline detergent compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises heating an aqueous solution containing trisodiurn phosphate and anhydrous sodium carbonate in proportions equivalent to 2 parts of normal trisodium phosphate to 1 of sodium carbonate to dehydrate the same to form a stable product containing about 25.74% of water and consisting largely of a hydrated compound of sodium phosphate and sodium carbonate.

9. As a new product, a readily soluble, noncaking non-hygroscopic alkaline detergent material consisting principally of a hydrated complex of trisodium phosphate and sodium carbonate, said product containingjrom about 18 to about 26% of water in stable combination and having initially a ratio of from 0.5 to 1.8 phosphate groups to each carbonate group.

10. As a new product, a readily soluble, noncaking, non-hygroscopic alkaline detergent material in finely divided form consisting principally of a hydrated complex of trisodium phosphate and sodium carbonate, said product containing about 20% of water in stable combination and having initially a ratio of phosphate groups to carbonate groups of from about 1.2:1.

11. As a new product, a readily soluble, noncaking, non-hygroscopic alkaline detergent material in ilne'ly divided form consisting principally of a hydrated complex of trisodium phosphate and sodium Icarbonate, said product containing from about 18 to about 26% of water in stable combination and a ratio of phosphate groups to carbonate groups of from 1 to 125:1.

12. As a new product, a readily soluble, noncaking, non-hygroscopic alkaline detergent material in finely divided form consisting principally of a hydrated complex of trisodium phosphate and sodium carbonate, said product containing from about 18 to about 26% of water in stable combination and a ratio of 0.5 to 1.25 phosphate groups to each carbonate group.

13. As a new product, a readily soluble, noncaking, non-hygroscopic alkaline detergent material in finely divided form consisting principally of a hydrated complex of trisodium phosphate and sodium carbonate, said product containing irom about 20 to about 23% of water in stable combination and a ratio of from 1 to 1.25 phosphate groups to each carbonate group.

14. The method of forming a stable alkaline detergent compound comprising principally a hydrated sodium phosphate and carbonate complex which comprises admixing a trisodium phosphate anda, sodium carbonate compound of the class consisting of sodium carbonate and sodium sesquicarbonate and their hydrates in proportions to provide a ratio oi.' from about 0.5 to about 1.8 phosphate groups to each carbonate group, adding water to the mixture in proportions of from about 45 to about 150% by weight of the mixture to at least form a slurry and dehydrating the resulting mixture to form a normally solid, pulverizable product containing in stable LLOYD A. HALL. CARROLL L. GRIFFTI'H.

CERTIFICATE oF CORRECTION.

January 5:' 1959- --LL'CIDA, RALLfETAL. l

It is hereby Cetified thai: erroIf-appeara 1n the printed speCificab-ion of the abCvC mnnberd patent requiring Correction as" f o11ofw's: Pag 5 first Immune 51', for; "lolocm," rudio-10 om.; and that-thaleia Letters Patent shuld pe read with tlzhis'correction therenthat the same may" :onfomtC the rc'ord of the case 1n the 118mm;y offICe.

l signed and Beaded this agtn'dgy of Februry, A.D.-1959." 

